Hello,

Thank you for the screenshots shared ! They clearly define what is your goal. However such behavior is not supported in WebHierarchicalDataGrid out of the box. I mean do not take this as something is not supported by the new control, but rather consider that they do not share a common architecture and since some behaviors/functionalities/code have their alternatives in WDG, others don't.

To achieve such view you will need to implement your own custom modification of the grid DOM, which is not recommended and does not seem to be a consistent solution.

Regarding your other question - expanding/collapsing though code behind:

You can use the ExpandAll method, which will Expands all rows out to what the grid is currently bound to (and collapsing though the CollapseAll method):

this.WebHierarchicalDataGrid1.ExpandAll();

this.WebHierarchicalDataGrid1.CollapseAll();

You can also manage the expanded rows by setting the InitialExpandDepth property, or set this indiviadually for each row( the example uses the DataBound event)

protected void WebHierarchicalDataGrid1_DataBound(object sender, EventArgs e)
    {
        this.WebHierarchicalDataGrid1.GridView.Rows[1].Expanded = true;
    }

Please let me know if you have further questions on the matter.